17915
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 21504
- Proper Divisor Sum (Aliquot Sum)
- 3589
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14328
- Möbius Function
- 1
- Radical
- 17915
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 97
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = Sum_{k=1..n} Sum_{j=1..k} (prime(k) - prime(j))^2.at n=11A062022
- a(n) = 2*a(n-1) + a(n-2) + 3*a(n-3), a(0)=1.at n=10A190140
- Number of nondecreasing sequences of n 1..6 integers with no element dividing the sequence sum.at n=31A212866
- G.f. A(x) satisfies: 1+x = A(x)^2 + A(x)^6 - A(x)^7.at n=5A249930
- Number of steps J. H. Conway's Fractran program needs to calculate the n-th prime.at n=8A267572
- a(1) is 4. a(n) is the least semiprime q (A001358) greater than p = a(n-1), such that p/q is a new minimum.at n=11A277343
- Numerator of variance of first n primes.at n=11A301275
- Numbers k whose digits d_1...d_m satisfy k = Sum_{i=1..m} i * d_i^i.at n=11A389243